I agree with the above posters that you need to deal with tune up and service issues first. You should change, in this order:
1. Engine oil.
2. Transmission fluid (I used Mercon V).
3. Coolant (flush the radiator also).
4. PCV valve.
5. Spark plugs and wires.
6. Distributer cap and rotor.
7. Fuel filter.
8. Air filter.
9. Differential fluid.
Make sure you thorougly inspect all brake components, suspension components, and hoses to make sure they're okay.
If your car feels strong, start into modifying it. If it still feels weak, you may want to go with a new MAF (mine was fried when I first bought my 95 GT and the Pro-M 75mm MAF I bought to replace it made the car ALOT faster) and new oxygen sensors.
Modification wise, I say **** the little **** that isn't going to do much anyway. Buy 4.10 gears to help that AODE and an off-road H-pipe (no catalytic converters) first. The car will really wake up at this point.
Next, buy a new fuel pump (at least 190lph) and an adjustable fuel pressure regulator. Install them, then buy the Zex dry kit you were wondering about (I have it, it's great). Start with the 75 shot and work from there.
As it sits, your car probably runs high 15s. If you do everything I suggested, you should go low 13s easily and blow most peoples doors off while enjoying the breeze in your face.
It doesn't take much to make these cars run, if you hit the right areas.
My car should do high 12s. I've only been to the track once, and I was more or less just learning what to do. I was losing .3-.4 off of my ET from stupid mistakes. Now that I have some kind of experience, I should be able to do much better.